A remote viewing device, such as an endoscope or a borescope, often is characterized as having an elongated and flexible insertion tube or probe with a viewing head assembly at its forward (i.e., distal) end, and a control section at its rear (i.e., proximal) end. Typically, the insertion tube is about 5 to 100 feet in length and approximately one-sixth to one-half inch in diameter, but it can have dimensions outside of these ranges as well. The viewing head assembly includes an optical tip and an imager, wherein at least one lens is spaced apart from, but is positioned relative to (e.g., axially aligned with) the imager. One or more light sources (e.g., one or more light emitting diodes) are disposed within the insertion tube, generally at or near the distal end thereof.
During use of a remote viewing device, image information is communicated from its viewing head assembly, through its insertion tube, and to its control section. In particular, light from the one or more light sources is transmitted out of viewing head assembly and, in return, image information representative of the inspection area is communicated to the imager (e.g., a CCD or CMOS camera assembly) via the at least one lens. This image information is processed and then outputted to a video monitor for viewing by an operator of the remote viewing device.
Different types of remote viewing devices generally are used for different purposes and in different settings. For example, an endoscope generally is used for remotely viewing the interior portions of a body cavity, such as for the purpose of medical diagnosis or treatment, whereas a borescope generally is used for remotely viewing interior portions of objects (e.g., industrial equipment, engines), such as for inspection purposes.
Certain parts of a remote viewing device are heat sensitive, such that they cease to function either entirely or at a satisfactory level if exposed to temperatures above a certain threshold. For example, light emitting diodes, which often act as the one or more light sources for a remote viewing device, can start to degrade and fail at temperatures above 120° C. Moreover, portions of the viewing head (e.g., the imager) of a remote viewing device likewise can begin to perform suboptimally at temperatures at or near 80° C., and can be vulnerable to failure at temperatures as low as about 10° C.
This can be problematic when, as is often the case, the one or more light sources are positioned near the imager of the remote viewing device. In general, operating the one or more light sources at or near full power will produce a high illumination output, and, in turn, beneficially will provide a more accurate image of the area being inspected by the remote viewing device. However, doing so also will cause the light source(s) to radiate heat, which can be at or above 100° when reaching the nearby imager. This creates a Catch-22 of sorts whereby one can operate the light source(s) at or near full power, thus obtaining advantageous results but risking damage to the nearby imager, or, instead, one can operate the light source(s) at less than full power, thus avoiding the potential to cause temperature-related harm to the imager but also ensuring that the obtained results will be suboptimal.
Another temperature-related problem can occur due to the usage environment of the remote viewing device. Whereas endoscopes tend to be utilized in settings at or near room temperature, borescopes often are employed in higher temperature usage environments, such as when performing inspections of aircraft engines or industrial equipment. If these inspections occur soon after the aircraft or equipment has finished its most recent operation, then the temperature environment being inspected can be well above the safe upper threshold of one or both of the at least one light source and the imager. This also creates a Catch-22 whereby one is forced either to wait to perform such inspections until the engine or equipment has definitely cooled below a temperature that could potentially harm the light source and/or the imager, thus disadvantageously requiring the aircraft or equipment to be non-operational during the waiting period, or, instead, to perform an inspection on a hot engine or piece of equipment, thus risking temperature-related harm to the light source and/or to the imager of the borescope.
Therefore, a need exists for systems and methods that would enable one to utilize a remote viewing device in a wider range of temperature environments and while operating its one or more light sources at or near full power without fear of causing temperature-related harm to the one or more light sources and/or to the imager, even if the imager is positioned nearby the one or more light sources.